CN102021479A - Si-containing medium carbon steel and thermal treatment method for Si-containing medium carbon steel to obtain high strength and elasticity - Google Patents
Si-containing medium carbon steel and thermal treatment method for Si-containing medium carbon steel to obtain high strength and elasticity Download PDFInfo
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- CN102021479A CN102021479A CN 201010602346 CN201010602346A CN102021479A CN 102021479 A CN102021479 A CN 102021479A CN 201010602346 CN201010602346 CN 201010602346 CN 201010602346 A CN201010602346 A CN 201010602346A CN 102021479 A CN102021479 A CN 102021479A
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Abstract
The invention discloses Si-containing medium carbon steel and a thermal treatment method for Si-containing medium carbon steel to obtain high strength and elasticity, which belongs to the technical field of medium carbon steel. The Si-containing medium carbon steel comprises the following chemical components in percentage by weight: 0.5-0.7% of C, 1.2-1.8% of Si, 0.4-0.8% of Mn, 0.2-0.4% of Cr, less than or equal to 0.013% of P, less than or equal to 0.005% of S, and the balance of Fe. The thermal treatment method comprises the following steps: austenitizing the components at the temperature of between 850 and 900 DEG C for 10-20 minutes; quickly putting the austenitized materials in salt liquid at 250-350 DEG C and performing salt bath quenching for 20-60 minutes; fetching the materials from the salt liquid at 250-350 DEG C and putting in an air furnace at 250-350 DEG C and preserving heat for 10-20 minutes; and fetching the materials and cooling with water to room temperature. The invention has the advantages: high-strength and high-elasticity lower bainite and stable austenite structure are obtained from the materials; relatively high toughness is realized; the complicated thermal treatment of users is replaced; the heat-preservation part of a resistor furnace replaces the isothermal time of isothermal quenching in the salt bath furnace; the pressure in the salt bath furnace is reduced; the salt bath quenching technique is optimized; the steel strength exceeds 1,500 MPa; and the area reduction is over 40%.
Description
Technical field
The invention belongs to the medium carbon steel technical field, particularly relate to a kind of Si of containing medium carbon steel and obtain the heat treating method of high-strength high-ductility, obtain the thermal treatment process of lower bainite+stable austenite tissue and high-strength high-ductility at material.
Background technology
The thermal treatment of medium carbon steel is engineering and the research of produce going up emphasis always, and traditional thermal treatment process mainly is a quenchings+tempering process, and the most typical is exactly the salt bath processing that is used for cold-heading fastening piece Q-tempering and grinding tool, cutlery.This thermal treatment obtains tempered martensite, tempering troostite and tempered sorbite according to processing requirement and environment for use, according to user's requirement, adjust to quench and the tempered processing parameter can make tissue possess high strength, high-ductility, premium properties such as impelling strength and slackness preferably.What this wherein related to is the schedule of reinforcement of metallic substance, in general, mainly contain solution strengthening, refined crystalline strengthening, precipitation strength, dislocations strengthening, phase transformation strengthening etc., so, the heat treatment reinforcement mode belongs to solution strengthening and precipitation strength, but has the heat treatment step complexity all the time, and energy consumption is big, the cost height is strengthened shortcomings such as limited in one's ability.Add insulation by the salt bath cooling and handle acquisition lower bainite+stable austenite structure, the solution strengthening and the dislocations strengthening of the unitary refined crystalline strengthening of bainite, bainite ferrite supersaturation carbon have been brought into play, also utilized simultaneously the stable austenitic build up in back, can partly substitute the tempering process of quenching, make material possess better intensity and toughness.
In addition, the salt bath soaking time is the subject matter that influences engineering and production always, patent " a kind of industrial 9SiCr is the isothermal heat treatment process of lower bainite in short-term " has also been told about a kind of heat-treatment technology method that obtains the favorable comprehensive mechanical property index by salt bath, but the shortest needs of salt bath isothermal time 5 minutes, the salt bath time is oversize, patent " contains molybdenum bainite low alloy steel and thermal treatment process " has also introduced a kind of salt bath process that obtains bainite, but material itself is except the Mo alloying element that adds a large amount of costlinesses, the transition process of tissue also is to finish in salt bath, treatment time is very long, has limited these technologies to a great extent in industrial application prospect.
Well-known alloying element Si and C are less expensive, the also relatively good control of smelting process composition, manufacturing cost is relatively low, if can utilize this material to realize that the mechanical property of high-strength high-ductility partly substitutes the technology of prior heat treatment simultaneously, has good development prospect undoubtedly, key is that analysis is gone in the effect of this alloy material salt bath and isothermal process, and clear and definite each operation stage is to the influence of material structure transition process.Stage of breeding before the nucleation process of lower bainite and forming core initial stage guarantee relatively stable processing parameter, it is finished in salt bath furnace, after satisfying lower bainite and organizing thermodynamic condition, its bainitic transformation process is finished (considering industrial air Control for Kiln Temperature precision) under the process window of relative broad, promptly in the air thermal preservation stove, finish, in this course, both realized structural transformation, simultaneously remaining residual austenite is realized stabilization procedures, and the traditional technology stabilization temperature is lower relatively.Traditional stabilization procedures always in material cooled to room temperature, reheat is to the stabilization process temperature, long-time insulation, and the present invention simplifies this process, when reaching material to resistance toheat, relaxation property requirement, technology is simpler.
The present invention is analysing in depth on a kind of basis that contains Si medium carbon steel bainitic transformation thermodynamics and kinetics, realize separating of quick cooling of salt bath and heat insulation function, considering to realize the high-strength high-ductility of metallic substance under the prerequisite of actual big working condition to greatest extent.Though a lot of to the bainitic transformation and the isothermal quenching research of steel both at home and abroad, do not contain the thermal treatment process report that the Si steel obtains lower bainite+stable austenite about middle carbon.
Summary of the invention
The object of the present invention is to provide a kind of Si of containing medium carbon steel and obtain the heat treating method of high-strength high-ductility, make material obtain lower bainite and stable austenite, when improving the strength of materials, make material more possess plasticity preferably, reduce the prior heat treatment high energy consumption, optimized bainite salt bath quenching technology.
The Si of containing medium carbon steel chemical constitution of the present invention is: C:0.5～0.7wt%, and Si:1.2～1.8wt%, Mn:0.4～0.8wt%, Cr:0.2～0.4wt%, P≤0.013wt%, S≤0.005wt%, surplus is Fe.
Thermal treatment process is: the first step is that austenitizing is handled, and material is carried out conventional resistance furnace be heated to 850-900 ℃ under air atmosphere, is incubated 10-20 minute; Second step was austenitic quick cooling process, material was put into fast 250-350 ℃ saline solution insulation 40-60 second; 250-350 ℃ of insulation carried out in insulation after the 3rd step isothermal quenching in the resistance furnace of routine, soaking time is 5-20 minute, obtains lower bainite and stabilization austenite, and last water-cooled is to room temperature.More than three the step all in air ambient, carry out.
The invention has the advantages that the first step and the 3rd step are to finish in resistance heading furnace, second step finished in salt bath furnace.Both realized that material obtained the lower bainite of high-strength high-ductility+stabilization austenite structure, obtain better strength and toughness, the alternate user complicated heat treatment, replace isothermal quenching isothermal time in salt bath furnace with the resistance furnace insulating sections simultaneously, reduced the production pressure of salt bath furnace, optimized salt bath quenching technology, process stabilizing, environmental protection and energy saving.
Obtain lower bainite and stabilization austenite structure (as shown in Figure 1, 2) by the bainite transformation in quick cooling of the salt bath behind 850-900 ℃ of austenitizing and the holding furnace, the intensity and the plasticity of material have been improved, reduce energy consumption, optimized bainitic hardening technology; Intensity is reached more than the 1500Mpa, and reduction of area reaches more than 40%.
Description of drawings
Fig. 1 organizes photo (300 ℃) for lower bainite and the austenitic scanning electron microscope of stabilization that the present invention obtains.Can find that two kinds are organized main bainite and residual austenite, the technology difference of processing, obvious variation also takes place in tissue morphology, and salt temperature is low more, and the unitary size of bainite is more little.
Fig. 2 organizes photo (250 ℃) for lower bainite and the austenitic scanning electron microscope of stabilization that the present invention obtains.
Fig. 3 obtains the thermal treatment process figure of high-strength high-ductility for a kind of Si of containing medium carbon steel.Wherein,
T
A: austenitizing temperature, 850-900 ℃;
T
B: salt bath quenching temperature, 250-350 ℃;
T
c: holding temperature, 250-350 ℃;
t
0: austenite treatment time, 20 minutes;
t
1: salt bath quenching time 40-60 second;
t
2: soaking time, 10-20 minute.
Be described in detail with reference to accompanying drawing below with reference to example of the present invention.
Fig. 4 is the drawing stress strain curve (300 ℃) of material.
Fig. 5 is the drawing stress strain curve (250 ℃) of material.
Fig. 6 is the drawing fracture apperance of material, is divided into pars fibrosa, radiation area, shear lip, is typical placticity failure fracture apperance.
Fig. 7 is the internal structure (300 ℃) of austenite after stable, and dislocation is stabilized in the black strip austenite band.
Embodiment
Heat treatment process of the present invention is: the material austenitizing, salt bath cooling then, be chilled to the Lower Bainite Transformation interval, carry out isothermal phase change entering the air thermal preservation stove, obtain lower bainite+stabilization austenite structure and good comprehensive mechanical properties in Shoudu Iron and Steel Co salt bath laboratory.Its chemical ingredients is as shown in the table:
Table 1 material chemical composition, surplus Fe.
| Element | C | Si | Mn | Cr | P | S |
| Content | 0.5％ | 1.4％ | 0.4％ | 0.3％ | 0.013％ | 0.004％ |
Heat treatment process divided for three steps finished:
The first step, austenitizing is handled, and is to use conventional resistance furnace to be heated to 850 ℃ of isothermals 20 minutes under air conditions to material, makes material obtain uniform austenite structure.
In second step, salt bath is handled behind the austenitizing, is material is chilled to lower bainite transition temperature interval fast from 850 ℃, is incubated 40 seconds, obtains uniform supercooled austenite.
The 3rd step, lower bainite and stabilization austenitic transformation, the cooled material of salt bath put into 300 ℃ air thermal preservation stove insulation 5 minutes, lower bainite takes place to be changed and stabilization of austenite (as Fig. 1 and Fig. 7), water-cooled is to room temperature then, intensity reaches about 1600Mpa, and unit elongation 10.8% (Fig. 4), reduction of area reach 45% (Fig. 6).
More than said three the step preferably carry out at air ambient.
Heat treatment process divided for three steps finished:
The first step, austenitizing is handled, and is to use conventional resistance furnace to be heated to 900 ℃ of isothermals 10 minutes under air conditions to material, makes material obtain uniform austenite structure.
In second step, salt bath is handled behind the austenitizing, is material is chilled to lower bainite transition temperature interval fast from 850 ℃, is incubated 60 seconds, obtains uniform supercooled austenite.
The 3rd step, lower bainite and stabilization austenitic transformation, the cooled material of salt bath put into 250 ℃ air thermal preservation stove insulation 20 minutes, lower bainite takes place to be changed and stabilization of austenite (Fig. 2), water-cooled is to room temperature then, intensity reaches about 1700Mpa, unit elongation 10.5% (Fig. 4), and reduction of area reaches 37%.
More than said three the step preferably carry out at air ambient.
By Fig. 4 and Fig. 5 material stage of tensile elasticity sex change before this as can be seen, stress is along with strain sharply increases, after enter the stretching platform, material slowly increases in certain stress range, and material structure can change in this phase process, generally includes soft mutually ferritic deformation, the long-range motion of dislocation, residual austenite is to the generation of deformation induced property phase transition process such as martensitic transformation, and last stress sharply descends, the material failure fracture.
Claims (2)
1. a kind of Si medium carbon steel that contains is characterized in that chemical constitution is: C:0.5～0.7wt%, and Si:1.2～1.8wt%, Mn:0.4～0.8wt%, Cr:0.2～0.4wt%, P≤0.013wt%, S≤0.005wt%, surplus is Fe.
2. the described Si of the containing medium carbon steel of claim 1 obtains the heat treating method of high-strength high-ductility, it is characterized in that processing step is: the first step is that austenitizing is handled, and treatment temp is 850-900 ℃, insulation 10-20min; Second step was incubated 40-60s for the material of above-mentioned austenitizing is put into 250-350 ℃ saline solution fast; The 3rd step was the material behind the above-mentioned salt bath to be put into 250-350 ℃ retort furnace be incubated 5-20min, and water-cooled is to room temperature then;
The described Si of containing medium carbon steel chemical constitution is: C:0.5～0.7wt%, and Si:1.2～1.8wt%, Mn:0.4～0.8wt%, Cr:0.2～0.4wt%, P≤0.013wt%, S≤0.005wt%, surplus is Fe.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103343280A (en) * | 2013-07-15 | 2013-10-09 | 凌伯勇 | Low-temperature quenching method for medium-carbon steel workpiece |
| CN105886714A (en) * | 2014-10-20 | 2016-08-24 | 重庆长安工业(集团)有限责任公司 | 50 steel ultrafine martensite isothermal quenching thermal treatment hardening process |
| CN106460084A (en) * | 2014-05-23 | 2017-02-22 | 麦格纳国际公司 | Austempering of structural components |
| CN106521350A (en) * | 2016-11-21 | 2017-03-22 | 河北工业大学 | Preparation method of high-tenacity medium-and-high-carbon superfine bainite steel |
| CN109355578A (en) * | 2018-12-14 | 2019-02-19 | 辽宁衡业高科新材股份有限公司 | A kind of preparation method of 1000MPa rank heat treatment wheel |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1624181A (en) * | 2004-12-15 | 2005-06-08 | 宁波浙东精密铸造有限公司 | Strongtough high gilicon cast steel and its manufacturing method |
| CN1904086A (en) * | 2006-08-03 | 2007-01-31 | 上海交通大学 | Method of improving steel object surface hardness using carbon distribution |
| CN101139645A (en) * | 2007-10-23 | 2008-03-12 | 天津理工大学 | Short-time lower bainite isothermal heat treatment process for industrial 9SiCr steel |
| CN101386958A (en) * | 2007-09-14 | 2009-03-18 | 首钢总公司 | Steel for high speed rail non-slag concrete slab sleeper steel wire and producing method thereof |
-
2010
- 2010-12-13 CN CN2010106023460A patent/CN102021479B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1624181A (en) * | 2004-12-15 | 2005-06-08 | 宁波浙东精密铸造有限公司 | Strongtough high gilicon cast steel and its manufacturing method |
| CN1904086A (en) * | 2006-08-03 | 2007-01-31 | 上海交通大学 | Method of improving steel object surface hardness using carbon distribution |
| CN101386958A (en) * | 2007-09-14 | 2009-03-18 | 首钢总公司 | Steel for high speed rail non-slag concrete slab sleeper steel wire and producing method thereof |
| CN101139645A (en) * | 2007-10-23 | 2008-03-12 | 天津理工大学 | Short-time lower bainite isothermal heat treatment process for industrial 9SiCr steel |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103343280A (en) * | 2013-07-15 | 2013-10-09 | 凌伯勇 | Low-temperature quenching method for medium-carbon steel workpiece |
| CN103343280B (en) * | 2013-07-15 | 2015-05-27 | 凌伯勇 | Low-temperature quenching method for medium-carbon steel workpiece |
| CN106460084A (en) * | 2014-05-23 | 2017-02-22 | 麦格纳国际公司 | Austempering of structural components |
| CN105886714A (en) * | 2014-10-20 | 2016-08-24 | 重庆长安工业(集团)有限责任公司 | 50 steel ultrafine martensite isothermal quenching thermal treatment hardening process |
| CN106521350A (en) * | 2016-11-21 | 2017-03-22 | 河北工业大学 | Preparation method of high-tenacity medium-and-high-carbon superfine bainite steel |
| CN109355578A (en) * | 2018-12-14 | 2019-02-19 | 辽宁衡业高科新材股份有限公司 | A kind of preparation method of 1000MPa rank heat treatment wheel |
| CN109355578B (en) * | 2018-12-14 | 2022-02-18 | 辽宁衡业高科新材股份有限公司 | Preparation method of 1000 MPa-level heat-treated wheel |
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Address after: 100041 Shijingshan Road, Shijingshan District, Shijingshan District, Beijing Patentee after: Shougang Group Co. Ltd. Address before: 100041 Shijingshan Road, Shijingshan District, Shijingshan District, Beijing Patentee before: Capital Iron & Steel General Company |